For many years, golf balls have been categorized into three different groups. These groups are, namely, one-piece or unitary balls, wound balls, and multi-piece solid balls.
A one-piece ball typically is formed from a solid mass of moldable material, such as an elastomer, which has been cured to develop the necessary degree of hardness, durability, etc., desired. The one-piece ball generally possesses the same overall composition between the interior and exterior of the ball. One piece balls are described, for example, in U.S. Pat. No. 3,313,545; U.S. Pat. No. 3,373,123; and U.S. Pat. No. 3,384,612.
A wound ball has frequently been referred to as a “three-piece ball” since it is produced by winding vulcanized rubber thread under tension around a solid or semi-solid center to form a wound core. The wound core is then enclosed in a single or multi-layer covering of tough protective material. Until relatively recently, the wound ball was desired by many skilled, low handicap golfers due to a number of characteristics.
For example, the three-piece wound ball was previously produced utilizing a balata, or balata like, cover which is relatively soft and flexible. Upon impact, it compresses against the surface of the club producing high spin. Consequently, the soft and flexible balata covers along with wound cores provide an experienced golfer with the ability to apply a spin to control the ball in flight in order to produce a draw or a fade or a backspin which causes the ball to “bite” or stop abruptly on contact with the green. Moreover, the balata cover produces a soft “feel” to the low handicap player. Such playability properties of workability, feel, etc., are particularly important in short iron play and low swing speeds and are exploited significantly by highly skilled players.
However, a three-piece wound ball has several disadvantages both from a manufacturing standpoint and a playability standpoint. In this regard, a thread wound ball is relatively difficult to manufacture due to the number of production steps required and the careful control which must be exercised in each stage of manufacture to achieve suitable roundness, velocity, rebound, “click”, “feel”, and the like.
Additionally, a soft thread wound (three-piece) ball is not well suited for use by the less skilled and/or high handicap golfer who cannot intentionally control the spin of the ball. For example, the unintentional application of side spin by a less skilled golfer produces hooking or slicing. The side spin reduces the golfer's control over the ball as well as reduces travel distance.
Similarly, despite all of the benefits of balata, balata covered balls are easily “cut” and/or damaged if mishit. Consequently, golf balls produced with balata or balata containing cover compositions can exhibit a relatively short life span. As a result of this negative property, balata and its synthetic substitute, trans-polyisoprene, and resin blends, have been essentially replaced as the cover materials of choice by golf ball manufacturers by materials comprising ionomeric resins and other elastomers such as polyurethanes.
Multi-piece solid golf balls, on the other hand, include a solid resilient core and a cover having single or multiple layers employing different types of material molded on the core. The core can also include one or more layers. Additionally, one or more intermediate layers can also be included between the core and cover layers.
By utilizing different types of materials and different construction combinations, multi-piece solid golf balls have now been designed to match and/or surpass the beneficial properties produced by three-piece wound balls. Additionally, the multi-piece solid golf balls do not possess the manufacturing difficulties, etc., that are associated with the three-piece wound balls.
The one-piece golf ball and the solid core for a multi-piece solid (non-wound) ball frequently are formed from a combination of elastomeric materials such as polybutadiene and other rubbers that are cross-linked. These materials are molded under high pressure and temperature to provide a ball or core of suitable compression and resilience. The cover or cover layers typically contain a substantial quantity of ionomeric resins that impart toughness and cut resistance to the covers. Additional cover materials include synthetic balatas, polyurethanes, and blends of ionomers with polyurethanes, etc.
As a result, a wide variety of multi-piece solid golf balls are now commercially available to suit an individual player's game. In essence, different types of balls have been, and are being, specifically designed to suit various skill levels. Moreover, improved golf balls are continually being produced by golf ball manufacturers with technological advancements in materials and manufacturing processes.
In this regard, the elastomeric composition of the core or center of a golf ball is important in that it affects several characteristics (i.e., playability, durability, etc.) of the ball. Additionally, the elastomeric composition provides resilience to the golf ball, while also providing many desirable properties to both the core and the overall golf ball, including weight, compression, etc.
Due to the continuous importance of improving the properties of a golf ball, it would be beneficial to form an elastomeric composition that exhibits improved properties, particularly improved combinations of compression and/or resilience, over known compositions. This is one of the objectives of the development disclosed herein.
This and other non-limiting objects and features of the development will be apparent from the following description and from the claims.